Method and system for controlling a mixed array of point-of-load regulators through a bus translator

ABSTRACT

A power control system comprises at least one point-of-load (POL) regulator adapted to provide an output voltage to a corresponding load and a system controller operatively connected to the at least one POL regulator via a data bus and adapted to send a first data message in a first format to the at least one POL regulator via the data bus. A bus translator is interposed along the data bus between the at least one POL regulator and the system controller. The bus translator converts the first data message from the first format to a second format that is compatible with the at least one POL regulator. The bus translator is adapted for bi-directional operation to convert a second data message communicated from the at least one POL regulator in the second format to the first format compatible with the system controller. The first and second data formats may comprise either a digital data format or an analog data format. The bus translator may further include a phase-locked loop circuit adapted to synchronize operation of the bus translator to a detected data rate of the data bus.

RELATED APPLICATION DATA

This application claims priority as a continuation-in-part pursuant to 35 U.S.C. § 120 to patent application Ser. No. 11/354,550, filed Feb. 14, 2006, which was in turn a continuation-in-part pursuant to 35 U.S.C. § 120 to patent application Ser. No. 10/326,222, filed Dec. 21, 2002.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to power control systems, or more particularly, to a method and system to control, program and monitor a mixed array of non-standard point-of-load regulators using a bus translator.

2. Description of Related Art

With the increasing complexity of electronic systems, it is common for an electronic system to require power provided at several different discrete voltage and current levels. For example, electronic systems may include discrete circuits that require voltages such as 3V, 5V, 9V, etc. Further, many of these circuits require a relatively low voltage (e.g., 1V), but with relatively high current (e.g., 100 A). It is undesirable to deliver relatively high current at low voltages over a relatively long distance through an electronic device for a number of reasons. First, the relatively long physical run of low voltage, high current lines consumes significant circuit board area and congests the routing of signal lines on the circuit board. Second, the impedance of the lines carrying the high current tends to dissipate a lot of power and complicate load regulation. Third, it is difficult to tailor the voltage/current characteristics to accommodate changes in load requirements.

In order to satisfy these power requirements, it is known to distribute an intermediate bus voltage throughout the electronic system, and include an individual point-of-load (“POL”) regulator, i.e., DC/DC converter, at the point of power consumption within the electronic system. Particularly, a POL regulator would be included with each respective electronic circuit to convert the intermediate bus voltage to the level required by the electronic circuit. An electronic system may include multiple POL regulators to convert the intermediate bus voltage into each of the multiple voltage levels. Ideally, the POL regulator would be physically located adjacent to the corresponding electronic circuit so as to minimize the length of the low voltage, high current lines through the electronic system. The intermediate bus voltage can be delivered to the multiple POL regulators using low current lines that minimize loss.

With this distributed approach, there is a need to coordinate the control and monitoring of the POL regulators of the power system. The POL regulators generally operate in conjunction with a power supply controller that activates, programs, and monitors the individual POL regulators. It is known in the art for the controller to use a multi-connection parallel bus to activate and program each POL regulator. For example, the parallel bus may communicate an enable/disable bit for turning each POL regulator on and off, and voltage identification (VID) code bits for programming the output voltage set-point of the POL regulators. The controller may further use additional connections to monitor the voltage/current that is delivered by each POL regulator so as to detect fault conditions of the POL regulators. A drawback with such a control system is that it adds complexity and size to the overall electronic system.

It is also known in the art to include within an electronic system various POL regulators of differing types and/or made by differing manufacturers. These various POL regulators may be configured to receive distinct or proprietary command and control instructions, therefore making it impossible to operate the non-standard POL regulators together within a common power control system. It is nevertheless desirable to coordinate the control over a mixed power system having a variety of differing types of POL regulators, however, conventional distributed power system do not provide flexibility to control such a mixed power system.

Thus, it would be advantageous to have a system and method for controlling and monitoring plural different types of POL regulators within a mixed power control system.

SUMMARY OF THE INVENTION

The present invention provides a system and method for controlling, programming and monitoring plural different types of POL regulators within a mixed power control system.

In an embodiment of the invention, a power control system comprises at least one point-of-load (POL) regulator adapted to provide an output voltage to a corresponding load and a system controller operatively connected to the at least one POL regulator via a data bus and adapted to send a first data message in a first format to the at least one POL regulator via the data bus. A bus translator is interposed along the data bus between the at least one POL regulator and the system controller. The bus translator converts the first data message from the first format to a second format that is compatible with the at least one POL regulator. The bus translator is adapted for bi-directional operation to convert a second data message communicated from the at least one POL regulator in the second format to the first format compatible with the system controller. The first and second data formats may comprise either a digital data format or an analog data format. The bus translator may further include a phase synchronization circuit adapted to synchronize operation of the bus translator to a detected data rate of the data bus or to synchronize the operation of the POL regulator.

A more complete understanding of the method and system for controlling and monitoring a mixed array of non-standard point-of-load regulators using a bus translator will be afforded to those skilled in the art, as well as a realization of additional advantages and objects thereof, by a consideration of the following detailed description of the preferred embodiment. Reference will be made to the appended sheets of drawings, which will first be described briefly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a prior art distributed power delivery system;

FIG. 2 depicts a prior art POL control system using a parallel control bus;

FIG. 3 depicts an exemplary POL control system constructed in accordance with an embodiment of the present invention;

FIG. 4 depicts an exemplary POL regulator of the POL control system;

FIG. 5 depicts an exemplary system controller of the POL control system;

FIG. 6 depicts an alternative embodiment of a POL control system in which plural non-standard POL regulators communicate with a common system controller using an exemplary bus translator;

FIG. 7 depicts another alternative embodiment of a POL control system in which plural non-standard POL regulators communicate with a common system controller using plural exemplary bus translators;

FIG. 8 depicts a block diagram of an exemplary bus translator for communicating between two serial data buses; and

FIG. 9 depicts a block diagram of an exemplary bus translator for communicating between a serial data bus and an analog data bus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides a system and method for controlling and monitoring POL regulators within a mixed power control system. In the detailed description that follows, like element numerals are used to describe like elements illustrated in one or more figures.

Referring first to FIG. 1, a prior art distributed power delivery system is shown. The prior art distributed power deliver system includes an AC/DC converter 12 that converts the available AC power into a primary DC power source, e.g., 48 volts. The primary DC power source is connected to a primary power bus that distributes DC power to plural electronic systems, such as printed circuit board 14. The bus may be further coupled to a battery 18 providing a back-up power source for the electronic systems connected to the primary power bus. When the AC/DC converter 12 is delivering DC power into the primary power bus, the battery 18 is maintained in a fully charged state. In the event of loss of AC power or fault with the AC/DC converter 12, the battery 18 will continue to deliver DC power to the primary power bus for a limited period of time defined by the capacity of the battery 18.

The printed circuit board 14 may further include a DC/DC converter that reduces the primary bus voltage to an intermediate voltage level, such as 5 or 12 volts. The intermediate voltage is then distributed over an intermediate power bus provided to plural circuits on the printed circuit board 14. Each circuit has an associated point-of-load (“POL”) regulator located closely thereby, such as POLs 22, 24, and 26. Each POL regulator converts the intermediate bus voltage to a low voltage, high current level demanded by the electronic circuit, such as 1.8 volts, 2.5 volts, and 3.3 volts provided by POLs 22, 24, and 26, respectively. It should be appreciated that the voltage levels described herein are entirely exemplary, and that other voltage levels could be selected to suit the particular needs of electronic circuits on the printed circuit board 14. By locating the POLs 22, 24, 26 close to their corresponding electronic circuits, the length of the low voltage, high current lines on the printed circuit board 14 are minimized. Moreover, the intermediate power bus can be adapted to carry relatively low current, thereby minimizing power loss due to the line impedance. But, this distributed power delivery system does not provide a way to monitor and control the performance of the POLs 22, 24, 26.

FIG. 2 illustrates a prior art DC/DC converter control system having a power supply controller 32 and a plurality of DC/DC converters 34, 36, 38, and 42. The DC/DC converters 34, 36, 38, and 42 are each connected to a power bus (as described above with respect to FIG. 1), which provides an input voltage. The DC/DC converters 34, 36, 38, and 42 each provide a low voltage, high current output that passes through respective sensing resistors 46, 52, 56, and 62 and respective switches 48, 54, 58, and 64. The controller 32 provides control signals to the DC/DC converters 34, 36, 38, and 42 via a plurality of six-bit parallel buses that each carry an enable/disable bit and five VID code bits. The VID code bits program the DC/DC converters for a desired output voltage/current level. The controller 32 also monitors the performance of the DC/DC converters 34, 36, 38, and 42 using the sensing resistors 46, 52, 56, and 62. Particularly, the controller 32 monitors the output voltage of each DC/DC converter by detecting the voltage at the output side of the sensing resistor, and monitors the output current through the sensing resistor by detecting the voltage across the sensing resistor. The voltage and current sensing for each DC/DC converter requires two separate lines, so eight separate lines are needed to sense the voltage and current condition of the exemplary four-converter system. Moreover, the controller 32 has a switch enable line connected to the gate terminals of switches 48, 54, 58, and 64, by which the controller 32 can shut off the output from any of the DC/DC controllers 34, 36, 38, and 42 or control the turn-on/off slew rate.

In an exemplary operation, the controller 32 provides control parameters (e.g., output voltage set-point) to the DC/DC converter 34 via the VID code portion of the six-bit parallel bus. The controller 32 then activates the DC/DC converter 34 via the enable/disable portion of the six-bit parallel bus. Once activated, the DC/DC converter 34 converts the power bus voltage (e.g., 48 volts) into a selected output voltage. The controller 32 then verifies that the output voltage is the desired voltage by measuring the voltage via the voltage monitoring line. If the output voltage is within an acceptable range, it is provided to the load (not shown) by activating the switch 48 via the switch enable line. The controller 32 can then continuously monitor the output voltage and the output current produced by the DC/DC converter 34 by measuring the output voltage via the voltage monitoring line and measuring the voltage drop across the sensing resistor (i.e., the voltage differential between the current monitoring line and the voltage monitoring line). If the controller 32 detects a fault condition of the DC/DC converter 34 (e.g., output voltage drops below a specific threshold), the controller 32 can disable and reset the DC/DC converter. The controller 32 communicates with the other DC/DC converters 36, 38, and 42 in the same manner.

A disadvantage with the control system of FIG. 2 is that it adds complexity and size to the overall electronic system by using a six-bit parallel bus to control each DC/DC converter and a separate three-line output connection to monitor the performance of each DC/DC converter. In other words, the controller 32 utilizes thirty-six separate connections in order to communicate with four DC/DC converters 34, 36, 38, and 42. As the complexity and power requirements of electronic systems increase, the number of connections to the controller will also increase in a linear manner.

Referring now to FIG. 3, a POL control system 100 is shown in accordance with an embodiment of the present invention. Specifically, the POL control system 100 includes a system controller 102, a front-end regulator 104, and a plurality of POL regulators 106, 108, 110, 112, and 114 arranged in an array. The POL regulators depicted herein include, but are not limited to, point-of-load regulators, power-on-load regulators, DC/DC converters, voltage regulators, and all other programmable voltage or current regulating devices generally known to those skilled in the art. An intra-device interface is provided between individual ones of the POL regulators to control specific interactions, such as current share or paralleling, e.g., current share interface (CS1) provided between POL0 106 and POL1 108, and CS2 provided between POL4 112 and POLn 114. In the exemplary configuration shown in FIG. 3, POL0 106 and POL1 108 operate in parallel mode to produce output voltage V_(O1) with increased current capability, POL2 110 produces output voltage V_(O2), and POL4 112 and POLn 114 operate in parallel mode to produce output voltage V_(O3), though it should be appreciate that other combinations and other numbers of POL regulators could be advantageously utilized.

The front-end regulator 104 provides an intermediate voltage to the plurality of POL regulators over an intermediate voltage bus, and may simply comprise another POL regulator. The system controller 102 and front-end regulator 104 may be integrated together in a single unit, or may be provided as separate devices. Alternatively, the front-end regulator 104 may provide a plurality of intermediate voltages to the POL regulators over a plurality of intermediate voltage buses. The system controller 102 may draw its power from the intermediate voltage bus.

The system controller 102 communicates with the plurality of POL regulators by writing and/or reading digital data (either synchronously or asynchronous) via a uni-directional or bidirectional serial bus, illustrated in FIG. 3 as the synch/data bus. The synch/data bus may comprise a two-wire serial bus (e.g., I²C) that allows data to be transmitted asynchronously or a single-wire serial bus that allows data to be transmitted synchronously (i.e., synchronized to a clock signal). In order to address any specific POL in the array, each POL is identified with a unique address, which may be hardwired into the POL or set by other methods. The system controller 102 also communicates with the plurality of POL regulators for fault management over a second uni-directional or bi-directional serial bus, illustrated in FIG. 3 as the OK/fault bus. By grouping plural POL regulators together by connecting them to a common OK/fault bus allows the POL regulators have the same behavior in the case of a fault condition. Also, the system controller 102 communicates with a user system via a user interface bus for programming, setting, and monitoring of the POL control system 10. Lastly, the system controller 102 communicates with the front-end regulator 104 over a separate line to disable operation of the front-end regulator.

An exemplary POL regulator 106 of the POL control system 10 is illustrated in greater detail in FIG. 4. The other POL regulators of FIG. 3 have substantially identical configuration. The POL regulator 106 includes a power conversion circuit 142, a serial interface 144, a POL controller 146, default configuration memory 148, and hardwired settings interface 150. The power conversion circuit 142 transforms an input voltage (V_(i)) to the desired output voltage (V_(O)) according to settings received through the serial interface 144, the hardwired settings 150 or default settings. The power conversion circuit 142 may also include monitoring sensors for output voltage, current, temperature and other parameters that are used for local control and also communicated back to the system controller through the serial interface 144. The power conversion circuit 142 may also generate a Power Good (PG) output signal for stand-alone applications in order to provide a simplified monitoring function. The serial interface 144 receives and sends commands and messages to the system controller 102 via the synch/data and OK/fault serial buses. The default configuration memory 148 stores the default configuration for the POL regulator 106, such as for use in cases where no programming signals are received through the serial interface 144 or hardwired settings interface 150. For example, the default configuration may be selected to cause the POL regulator 106 to operate in a “safe” condition in the absence of programming signals. Alternatively, the default configuration could be programmed to be the normal operating mode of the POL regulator to thereby minimize the need for additional programming signals from the system controller 102.

The hardwired settings interface 150 communicates with external connections to program the POL regulator without using the serial interface 144. The hardwired settings interface 150 may include as inputs the address setting (Addr) of the POL to alter or set some of the settings as a function of the address (i.e., the identifier of the POL), e.g., phase displacement, enable/disable bit (En), trim, and VID code bits. Further, the address identifies the POL regulator during communication operations through the serial interface 144. The trim input allows the connection of one or more external resistors to define an output voltage level for the POL regulator. Similarly, the VID code bits can be used to program the POL regulator for a desired output voltage/current level. The enable/disable bit allows the POL regulator to be turned on/off by toggling a digital high/low signal.

The POL controller 146 receives and prioritizes the settings of the POL regulator. If no settings information is received via either the hardwired settings interface 150 or the serial interface 144, the POL controller 146 accesses the parameters stored in the default configuration memory 148. Alternatively, if settings information is received via the hardwired settings interface 150, then the POL controller 146 will apply those parameters. Thus, the default settings apply to all of the parameters that cannot be or are not set through hard wiring. The settings received by the hardwired settings interface 150 can be overwritten by information received via the serial interface 144. The POL regulator can therefore operate in a stand-alone mode, a fully programmable mode, or a combination thereof. This programming flexibility enables a plurality of different power applications to be satisfied with a single generic POL regulator, thereby reducing the cost and simplifying the manufacture of POL regulators.

An exemplary system controller 102 of the POL control system 100 is illustrated in FIG. 5. The system controller 102 includes a user interface 122, a POL interface 124, a controller 126, and a memory 128. The user interface 122 sends and receives messages to/from the user (or host) via the user interface bus. The user interface bus may be provided by a serial or parallel bi-directional interface using standard interface protocols, e.g., an I²C interface. User information such as monitoring values or new system settings would be transmitted through the user interface 122. The communication with the user (or host) may be direct or via a local area network (LAN) or wide area network (WAN). A user may access the POL control systems for purposes of monitoring, controlling and/or programming the POL control systems by coupling directly to the user interface bus. The user system would likely include a user interface, such as a graphical user interface (GUI), that enables the display of status information regarding the POL control systems.

The POL interface 124 transforms data to/from the POL regulators via the synch/data and OK/fault serial buses. The POL interface 124 communicates over the synch/data serial bus to transmit setting data and receive monitoring data, and communicates over the OK/fault serial bus to receive interrupt signals indicating a fault condition in at least one of the connected POL regulators. The memory 128 comprises a non-volatile memory storage device used to store the system set-up parameters (e.g., output voltage, current limitation set-point, timing data, etc.) for the POL regulators connected to the system controller 102. Optionally, a secondary, external memory 132 may also be connected to the user interface 122 to provide increased memory capacity for monitoring data or setting data.

The controller 126 is operably connected to the user interface 122, the POL interface 124, and the memory 128. The controller 126 has an external port for communication a disable signal (FE DIS) to the front-end regulator 104. At start-up of the POL control system 100, the controller 126 reads from the internal memory 128 (and/or the external memory 132) the system settings and programs the POL regulators accordingly via the POL interface 124. Each of the POL regulators is then set up and started in a prescribed manner based on the system programming. During normal operation, the controller 126 decodes and executes any command or message coming from the user or the POL regulators. The controller 126 monitors the performance of the POL regulators and reports this information back to the user through the user interface 122. The POL regulators may also be programmed by the user through the controller 126 to execute specific, autonomous reactions to faults, such as over current or over voltage conditions. Alternatively, the POL regulators may be programmed to only report fault conditions to the system controller 102, which will then determine the appropriate corrective action in accordance with predefined settings, e.g., shut down the front-end regulator via the FE DIS control line.

A monitoring block 130 may optionally be provided to monitor the state of one or more voltage or current levels of other power systems not operably connected to the controller 102 via the synch/data or OK/fault buses. The monitoring block 130 may provide this information to the controller 126 for reporting to the user through the user interface in the same manner as other information concerning the POL control system 100. This way, the POL control system 100 can provide some backward compatibility with power systems that are already present in an electronic system.

Returning to FIG. 3, the system controller 102 is adapted to provide initial-configuration data to each POL regulator (i.e., 106, 108, 110, 112, 114). It should be appreciated that the initial-configuration data may include, but is not limited to, one or more of the following types of data: output-voltage-set-point-data (i.e., a desired output voltage); output-current-set-point data (i.e., the highest desired output current); low-voltage-limit data (i.e., the lowest desired output voltage); high-voltage-limit data (i.e., the highest desired output voltage); output-voltage-slew-rate data (i.e., the desired output slew rate); enable/disable data (i.e., turning on/off the POL regulator output); timing data (e.g., turn-on delay, turn-off delay, fault recovery time, etc.) and/or all other types of POL programming data generally known to those skilled in the art. Once the initial-configuration data is received, the POL controller 146 (see FIG. 4) is adapted to store at least a portion of the initial-configuration data in memory. At least a portion of the stored initial-configuration data is then used to produce a desired output. For example, an output may be produced to include a particular voltage level, a particular slew rate, etc., depending on the type of initial-configuration data received/stored.

After the output has been produced, the POL controller 146 is adapted to receive fault-monitoring data (e.g., from an external device, a sense circuit, etc.). The fault-monitoring data, which contains information on the POL regulator or its output, is then stored in the memory. The POL controller 146, in response to a condition (e.g., receiving a request, exceeding a known parameter, having a register's contents change, etc.), is then adapted to provide at least a portion of the fault-monitoring data to the system controller 102. It should be appreciated that the fault-monitoring data may include, but is not limited to, one or more of the following types of data: output-voltage data, which may include actual-output-voltage data (i.e., the measured output voltage) or voltage-comparison data (e.g., whether the measured output voltage is above or below the highest desired output voltage, whether the measured output voltage is above or below the lowest desired output voltage, etc.); output-current data, which may include actual-output-current data (i.e., the measured output current) or current-comparison data (e.g., whether the measured output current is above or below the highest desired output current); temperature-status data, which may include actual-temperature data (i.e., the measured temperature of a POL regulator, or more particularly its heat generating components) or temperature-comparison data (e.g., whether the temperature of the POL regulator (or its components) is above or below a known value, etc.), and/or all other types of POL fault monitoring data generally known to those skilled in the art. It should also be appreciated that fault-monitoring data is not limited to data representing the existence of a faulty condition. For example, fault-monitoring data that indicates that the POL regulator is operating within acceptable parameters (e.g., within an acceptable temperature range) is considered to be within the spirit and scope of the present invention.

The fault-monitoring data can be used by either the system controller 102 or the POL controller 146 to monitor and/or control the POL regulator. In other words, the POL controller 146 can use the fault-monitoring data to either provide POL status information (i.e., data corresponding to a particular POL regulator or its output) to the system controller 102 or disable the POL regulator if a particular condition is met (e.g., the status register changes, the temperature limit has been exceeded, etc.). Alternatively, the system controller 102 can use the fault-monitoring data to either provide POL status information to an administrator, disable a particular POL regulator, or store the fault-monitoring data for future use. For example, in one embodiment of the present invention, each POL regulator includes unique ID data (e.g., serial number, date of manufacture, etc.) stored in an ID register. This enables the system controller 102 to provide POL status information and unique ID data to an administrator.

In another embodiment of the present invention, each POL regulator further includes at least one sensor circuit. The sensor circuit is used to produce either the fault-monitoring data, or data that can be used (e.g., together with information stored in the memory) to produce the fault-monitoring data. It should be appreciated that the sensor circuit, as described herein, will vary (e.g., as to circuitry, location, inputs, etc.) depending upon the type of information that is being detected. For example, a sensor circuit that detects current may include different circuitry, have different inputs, and be placed in a different location than a sensor circuit that detects temperature.

The POL control system 10 enables four different modes of operation. In the first operational mode, the POL regulators function independently in the absence of a system controller and without interaction with other POL regulators. The POL regulators each include local feedback and control systems to regulate their own performance as well as control interfaces to enable local programming. The POL regulators further include default settings in which they can revert to in the absence of local programming or data from the system controller. In other words, each of the POL regulators can operate as a standalone device without the need for a system controller or interactions with another POL regulator.

In the second operational mode, the POL regulators interoperate for the purpose of current sharing or interleaving in the absence of a system controller. The POL regulators communicate with each other over the current share interface. The synch/data line may be used to communicate synchronization information to permit phase interleaving of the POL regulators, in which the phase is programmed locally by entering an address through hardwired connections. In either the first or second modes of operation, there would generally be information communicated between the POL regulators except for synchronization; there would be no need to communicate programming information.

In the third operational mode, the POL regulators operate as an array in which the behavior of each POL regulator and the array as a whole are coordinated by a system controller. The system controller programs the operation of each of the POL regulators over the synch/data serial bus, and thereby overrides the predetermined settings of the POL regulators. The synch/data serial bus is further used to communicate synchronization information to permit synchronization and interleaving of the POL regulators. This operational mode would not include interdevice communications over the current share interface.

Lastly, the fourth operational mode includes both central control using the system controller and local control over certain functionality. This way, the POL regulators operate as an array coordinated by a system controller and also interoperate with each other to perform functions such as current sharing.

In an embodiment of the invention, the POL regulators of a power control system would each be configured in a standardized manner so that data communicated between the POL regulators and the system controller would have a known format and protocol that is understood by all elements of the power control system. The selected data format/protocol may be proprietary such that only a single vendor's POL regulators would be able to communicate within the power control system. Alternatively, the data format/protocol may be defined by an open industry standard, so that different vendors could produce compatible POL regulators that could each operate within a standardized power control system.

In certain applications, however, it may be advantageous to permit the operation of various non-standardized POL regulators within a common power control system, including POL regulators that are adapted to communicate using different data formats or communication protocols, e.g., a mixed or non-standardized power control system. For example, an electronic system may include various component elements (e.g., POL regulators) that are provided by different vendors and that are not compatible in data format and/or protocol. Such a system may include a mix of legacy components that were provided at an earlier time alongside newer power control system components that are compatible with either a proprietary or open-standard data format/protocol. Nevertheless, it would still be desirable to coordinate the power control throughout the electronic system to achieve the aforementioned benefits of centralized control. Accordingly, the following embodiments of the invention provide solutions to permit a mixed power control system to interoperate together and achieve the same benefits of a standardized power control system.

Referring to FIG. 6, an exemplary embodiment of a mixed power control system is shown. As in the preceding embodiments, the power control system includes a system controller 202 that communicates with a plurality of POL regulators, including exemplary POL regulators POL1 204, POL2 206, POL3 208, and POL4 210. For purposes of this example, POL regulators POL3 208 and POL4 210 are compatible with the system controller 202, and the three elements communicate with each other through a serial data bus (termed Communication Interface 1). In contrast, POL1 204 and POL2 206 are not compatible with the system controller 202, such as due to difference of data format and/or protocol. POL1 204 and POL2 206 are each coupled to a separate data bus, which may be serial data or analog (termed Communication Interface 2). To provide interoperability between Communication Interface 1 and Communication Interface 2, a bus translator 220 is interposed therebetween. The bus translator 220 will receive data messages on one of the two interfaces, translate the data messages to the data format and/or protocol of the other interface, and then communicate the translated data messages onto the other interface. The bus translator 220 would be adapted to operate bi-directionally, so that data messages received in either direction would pass therethrough. With the bus translator 220 in place, POL1 204 and POL2 206 would be able to communicate with the system controller 202 as well as with POL3 208 and POL4 210 as if they were all part of a standard power control system.

FIG. 7 illustrates another exemplary embodiment of a mixed power control system. As in FIG. 6, the power control system includes a system controller 202 that communicates with exemplary POL regulators POL1 204, POL2 206, POL3 208, and POL4 210. POL regulators POL3 208 and POL4 210 are compatible with the system controller 202, and the three elements communicate with each other through a serial data bus (termed Communication Interface 1). POL1 204 and POL2 206 are not compatible with the system controller 202, nor are they compatible with each other, such as due to difference of data format and/or protocol. POL1 204 is coupled to a separate data bus (e.g., serial data or analog) (termed Communication Interface 2), and POL2 206 is coupled to another separate data bus (e.g., serial data or analog) (termed Communication Interface 3). Bus translator 220 is interposed between Communication Interfaces 1 and 2, and bus translator 230 is interposed between Communication Interfaces 1 and 3. As in the preceding embodiment, the bus translators 220, 230 will receive data messages on one of the two interfaces, translate the data messages to the data format and/or protocol of the other interface, and then communicate the translated data messages onto the other interface. The bus translators 220, 230 would be adapted to operate bi-directionally, so that data messages received in either direction would pass therethrough. This way, POL1 204 and POL2 206 would be able to communicate with the system controller 202 as well as with each other and with POL3 208 and POL4 210 as if they were all part of a standard power control system.

It should be appreciated that an actual power control system may have different numbers of POL regulators. In accordance with the present invention, the power control system could include both standard and non-standard POL regulators within a common power control system through the use of one or more bus translators. This would enable the system controller to communicate control data to the POL regulators and receive fault monitoring data in return. Moreover, the embodiments illustrated in FIGS. 6 and 7 reflected use of an exemplary bus translator in translating and propagating control data ordinarily communicated using the Synch/Data line (see FIG. 3). It should be appreciated that the same bus translator device could provide translation and propagation of signals communicated on the OK/Fault line.

Referring now to FIG. 8, an exemplary bus translator 220 is illustrated in greater detail. As described above, the bus translator 220 include two bidirectional communication interfaces (termed Communication Interface 1 and 2). Communication Interface 1 is coupled to transmit/receive unit 222 (comprising receive module 222A and transmit module 222B), and Communication Interface 2 is coupled to transmit/receive unit 226 (comprising receive module 226A and transmit module 226B). Each transmit/receive unit 222, 226 is in turn coupled to memory unit 224. The memory unit 224 may include a look up table, map, algorithms or other instructions for translating between data formats/protocols. As generally known in the art, the memory unit 224 may also include limited data processing logic suitable for controlling operation of the memory unit to search for, retrieve, and relay data values. In an exemplary operation, an incoming data message arriving from Communication Interface 1 is passed through receive module 222A to memory unit 224, whereupon the data message is translated and forwarded to receive unit 226A, which passes the translated data message onto Communication Interface 2. The same operation will occur in the reverse direction to translate data messages arriving from Communication Interface 2.

The bus translator 220 may further include a phase synchronization circuit 228 to control the timing of operation of the transmit/receive unit 222 and the memory unit 224. The phase synchronization circuit 228 could be based on a phase-locked loop circuit or could be interrupt driven. As known in the art, a phase-locked loop circuit responds to both the frequency and the phase of the input signals to automatically raise or lower the frequency of a controlled oscillator until it is matched to the reference in both frequency and phase. The exemplary phase synchronization circuit 228 would monitor the phase and frequency of the incoming data messages received on the Communication Interface 1, and thereby provide a clock signal to the transmit/receive unit 222 and the memory unit 224 so as to synchronize the timing of their operation. The phase synchronization circuit 228 may further provide the clock signal externally of the bus translator 220 so as to provide synchronization with other external systems, such as the pulse width modulators of POL regulators. In the case of an interrupt-driven phase synchronization circuit 228, incoming data or synchronization information would trigger specific actions in the bus translator 220 to assure synchronized operation of data translation and propagation.

FIG. 9 illustrates an alternative embodiment of a bus translator 240. As in the foregoing embodiment, the bus translator 240 includes two bidirectional communication interfaces; however, the first interface (termed Communication Interface 1) is adapted for digital signal communications and the second interface (termed Analog Interface) is adapted for analog signal communications. Communication Interface 1 is coupled to transmit/receive unit 242 (comprising receive module 242A and transmit module 224B) in the same manner as in FIG. 8. The Analog Interface is coupled to data conversion unit 246 (comprising digital-to-analog converter (DAC) 246A and analog-to-digital converter 246B). The transmit/receive unit 242 and data conversion unit 246 are each coupled to memory unit 244, which operates in substantially the same manner as described above. In an exemplary operation, a data message arriving from Communication Interface 1 is passed through receive module 242A to memory unit 244, whereupon the data message is translated and forwarded to DAC 246A, which converts the binary message to analog data values that are then passed onto the Analog Interface. The same operation will occur in the reverse direction to translate analog data values arriving from the Analog Interface. As in the preceding embodiment, the bus translator 240 may further include a phase synchronization circuit 248 in order to synchronize the operation of the transmit/receive unit 242 and memory unit 244 to incoming data messages.

Having thus described a preferred embodiment of a method and system to control, program and monitor a mixed array of non-standard point-of-load regulators using a bus translator, it should be apparent to those skilled in the art that certain advantages of the system have been achieved. It should also be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention. The invention is further defined by the following claims. 

1. A power control system comprising: at least one point-of-load (POL) regulator adapted to provide an output voltage to a corresponding load; a system controller operatively connected to the at least one POL regulator via a data bus and adapted to send a first data message in a first format to the at least one POL regulator via the data bus; and a bus translator interposed along the data bus between the at least one POL regulator and the system controller, the bus translator converting the first data message from the first format to a second format that is compatible with the at least one POL regulator.
 2. The power control system of claim 1, wherein the data bus further comprises a serial data bus.
 3. The power control system of claim 1, wherein the bus translator is adapted for bidirectional operation to convert a second data message communicated from the at least one POL regulator in the second format to the first format compatible with the system controller.
 4. The power control system of claim 3, wherein the second data message further comprises status monitoring data from the at least one POL regulator.
 5. The power control system of claim 1, wherein said second format comprises a digital data format.
 6. The power control system of claim 1, wherein said second format comprises an analog data format.
 7. The power control system of claim 1, wherein the bus translator further comprises a phase synchronization circuit adapted to synchronize operation of the bus translator to a detected data rate of the data bus.
 8. The power control system of claim 7, wherein the phase synchronization circuit further comprises a phase-locked looped circuit.
 9. The power control system of claim 7, wherein the phase synchronization circuit is driven by external event signals.
 10. The power control system of claim 1, wherein the bus translator further comprises a memory unit containing instructions for converting between the first and second formats.
 11. The power control system of claim 1, wherein the first data message further comprises programming data for the at least one POL regulator.
 12. A method of controlling a power control system, comprising: generating a first data message intended for at least one point of load (POL) regulator; translating the first data message from a first format to a second format that is compatible with the at least one POL regulator; propagating the translated first data message to the at least one POL regulator; and operating the at least one POL regulator to control a characteristic of an output voltage in accordance with the translated first data message.
 13. The method of claim 12, further comprising: generating a second data message at the at least one POL regulator intended for a power system controller; translating the second data message from the second format to the first format that is compatible with the power system controller; propagating the translated second data message to the system controller; and operating the power control system in accordance with the translated second data message.
 14. The method of claim 12, wherein said second format comprises a digital data format.
 15. The method of claim 12, wherein said second format comprises an analog data format.
 16. A bus translator for use in a power control system comprising at least one point-of-load (POL) regulator adapted to provide an output voltage to a corresponding load, and a system controller operatively connected to the at least one POL regulator and adapted to send a first data message in a first format to the at least one POL regulator, the bus translator being adapted to be interposed between the at least one POL regulator and the system controller, the bus translator translating the first data message from the first format to a second format that is compatible with the at least one POL regulator and propagating the translated first data message to the at least one POL regulator.
 17. The bus translator of claim 16, further adapted for bi-directional operation to convert a second data message communicated from the at least one POL regulator in the second format to the first format compatible with the system controller.
 18. The bus translator of claim 16, wherein said second format comprises a digital data format.
 19. The bus translator of claim 16, wherein said second format comprises an analog data format.
 20. The bus translator of claim 16, further comprising a phase synchronization circuit adapted to synchronize operation to a detected data rate of the data bus.
 21. The bus translator of claim 16, further comprising a memory unit containing stored instructions for converting between the first and second formats. 